Background & objective: It is possible that some important genes were overexpressed in esophageal carcinoma cells induced by nitric oxid(NO), but it is not yet clear which the genes are. The objective of this study was to separate and identify the overexpressive genes induced by NO in EC109 esophageal carcinoma cell line.
Methods: Overexpression of the genes induced by nitric oxid(NO) in EC109 esophageal carcinoma cell line was determined by using suppression subtractive hybridization(SSH). Sixty-nine positive clones were obtained by EcoR I digesting, and overexpressive genes were screened by reverse mRNA dot blot and further confirmed by Northern blot analysis. The nucleotide of their expressed sequence tag(EST) was sequenced and analyzed by using NCBI database.
Results: The two mitochondrial DNA coding genes, ND-4L and ND-4, were identified. The ND-4L and ND-4 genes were overexpressed distinctly in the EC109 cell induced by NO. The three point mutations were discovered in a fragment(10,736-11,449) of ND-4L and ND-4 genes.
Conclusion: NO can induce overexpression of the ND-4L and ND-4 genes which is coded by mitochondrial DNA. These results provide a new idea for further exploring the mechanism of NO effecting on carcinoma cells.